16Gb memory not shown in Bios

[korpponen]

Hi

I have Asus P8Z77-V LK mobo and four Kingston HyperX Red DDR3 1600Mhz 1.65V (two 8Gb kit, KHX16C9B1RK2/8X), and the trouble is only 8GB recognized in bios and windows 7 home 64-bit.

Case is Cooler Master Elite 430, PSU Cooler Master GX 750W, video card MSI Geforce 660 GTX.

Can plug in 2x4GB to Blue or black slots and get right amount 8Gb in bios. Can also plug in 2x4GB to first black and second blue slots and get correct 8GB in single channel mode. BUT when I plug in all 4x4GB bios is only shown 8GB (pc will still boot with all 4 sticks). When plugging in 3x4GB also only 8GB shown in bios.

In bios tool section all 4 ram sticks are shown. In windows CPU-Z reports 16GB.

Have read bent CPU pins or mobo shortcuts to metal case in many posts, but could it be that in my case too, my both memory channels do work, they just do not work at the same time.

Have tried:

- RAM voltage from 1.4 - 1.65V
- Have load optimized default in Bios and tried XMP profile, and tried to left it in Auto setting
- Have tried memory speeds 1333 and 1600MHz
- Have changed latencies from 9-9-9-27 to 11-11-11-30
- Receated memory dozens of times tryin different variations.

EDIT:

- Tested each mem slot with single Ram module, all ram modules and slots are working
- Updated Bios to latest version
- Cleared CMOS
- Checked CPU for bent pins, but everything was ok in the socket.

BUT CANT GET MORE THAN 8GB RECOGNIZED.

Any tips would be mostly appreciated

 

[alexoiu]

Hi,
With single RAM module test each slot. See if all of them do work.

 

[korpponen]

Will try that after getting home from work(which clearly disturbs my computer hobby )

 

[korpponen]

Ok, now I have tested all slots with single ram module. And pc post and boot without any troubles on all 4 slots using single ram module. Bios recognize size of module right.

 

[korpponen]

Forgot to mention that I have updated bios to latest 0908 version.

 

[alexoiu]

Try clearing the CMOS (unplug the power cord and remove the CMOS battery for few minutes). Then insert all 4 modules (one kit in the black slots and the other kit in the blue ones), restart and see if still the same.

 

[korpponen]

Still the same, 8 GB memory shown.

Sandra says:

BANK 0 - ChannelA - DIMM0 Empty
BANK 1 - ChannelA - DIMM1 Kingston KHX1600.... the right information
BANK 2 - ChannelB - DIMM0 Empty
BANK 3 - ChannelB - DIMM1 Kingston KHX1600.... the right information

CPU-Z sees all 16GB in dual channel mode

Next thing to do..attach a rope to computer case and make hammer throw world record? =)


Thank you for your fast answers.

 

[alexoiu]

It might be a CPU socket bent pins issue, but usually, in this case one or more slots would not work at all. Or in your case the slots do work. A memory controller issue? A board issue or a memory one? Hard to say.
If thermal paste and some spare time available, try reinstalling the CPU. Check the socket for bent pins.

 

[korpponen]

No bent pins found in the CPU socket.